This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Instrument maintenance performed on the (1) Finnigan LCQ Deca XP, (2) Finnigan LCQ Deca XP Plus, (3) Finnigan LTQ, (4) Finnigan LTQ-Orbitrap, (5) Sciex's QqTOF prototype, Centaur model, (6) Applied Biosystems QStar mass spectrometer, (7) Waters Synapt HDMS, (8) Perkin Elmer prOTOF 2000, (9) Pharmacia-Amersham Smart HPLC system, (10) LC Packings HPLC system, and (11) Micro-Tech Scientific XtremeSimple HPLC system. Service in the mass spectrometers included maintenance of vacuum pumps, cleaning of the ion source, replacement of ion detectors, repair of electronics;the HPLC systems required maintenance of piston and syringe pumps and replacement of seals, check valves, and trouble shooting.